


Slumber Party

by vanessa_cardui



Category: Original Work
Genre: Blackmail, F/F, Gang Rape, Humiliation, Multi, Orgasm Control, Sex Toys, Step-Sibling Incest, Strap-Ons
Language: English
Status: Completed
Published: 2017-07-13
Updated: 2017-07-13
Packaged: 2018-12-01 14:13:45
Rating: Explicit
Warnings: Rape/Non-Con, Underage
Chapters: 1
Words: 4,844
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11488044
Author URL: https://archiveofourown.org/users/vanessa_cardui/pseuds/vanessa_cardui
Summary: Grace isn't sure the thing she's got going with her stepsister Hailey is a good idea.  Especially now that Hailey's told all her friends that Grace is her sex slave, and will literally ruin her life if she doesn't play along.





	Slumber Party

**Author's Note:**

  * For [dentalhygienist](https://archiveofourown.org/users/dentalhygienist/gifts).



Grace had known that it was a bad idea from the beginning, but it had gotten worse. It was time to draw the line.

"No," she said.

"Aw, come on," said Hailey. "Look, I've already told my friends that you're my sex slave, and they're coming over tomorrow, so if you're not going to put out, I'm going to look like an idiot."

"Hailey," said Grace. "No. And I'm not your sex slave. I'm not even sure it's such a great idea that we're having sex in the first place--"

"What! First of all, it's not like we're related-related. Mom isn't even married to Dad, and isn't going to get married to Dad, and second of all--"

"Look, forget it," said Grace. "We were lonely, and--"

"Were?" said Hailey. "Fucking hell, Grace. I moved here two months ago. Do you know how hard it is to make friends when you transfer somewhere in 9th grade?"

"Hailey!" said Grace, trying to both make it clear how much it wasn't happening, and also not yell so loud that her mom would hear that she was yelling at Hailey, and want to know why. "You aren't going to guilt trip me into fucking your friends. If you . . . I mean, look. I'm not saying that we're going to stop doing this, it's just. . . no, Hailey. No."

Hailey scowled, and then went over to her computer. "Okay," she said. "But watch this."

It was the green-on-green night vision video that they'd made a week ago. Hailey was in bed, in her heart pyjamas. Grace came in, wearing a stupid black turtleneck and jeans, and slipped the pyjamas off of Hailey's butt.

She did have a pretty cute butt.

"What's your point?" said Grace.

"Well," said Hailey. "Doesn't look good, does it? I mean, innocent young girl, taking it hard in the ass while she sleeps--probably roofies, right?"

Grace was watching herself put on the strap-on. It was. . . "You were just pretending to be asleep, Hailey," she said. "This was your stupid fantasy."

"Yeah," said Hailey. "But my point is, that's not what it looks like."

"Hailey."

"It looks like a sixteen-year-old gave her younger stepsister sleeping pills, then raped her butt while she was out. It's not a great look for you. So, here's the deal. Told my friends that you're my sex slave, will literally ruin your life if you do not act like my sex slave. So you're my sex slave."

"You're bluffing?" said Grace, but even to her ears, that sounded like a question.

Hailey looked at her. She had the same fine-boned features as her father, but normally she looked warm and friendly. Now she looked as cold as he did when he was mad. She wasn't bluffing.

Grace's shoulder's slumped. "Hailey, please? I don't want to do this. I'll. . . please? I'll clean your room for you, or--"

"Yeah you will," said Hailey. "I mean, we've got a party coming up, so I'm going to be way too busy to do that. Oh, and it's on Thursday, so make sure that you wax and do your hair pretty. And also don't you dare masturbate without permission, because I swear to god, if you ruin this party for me, I am going to end you, Grace."

Grace looked for some sign of pity, or something, but Hailey was already on her phone, texting with one of the giggling crowd of girls she'd started hanging out with. "Also make sure you get your homework for the weekend done before the party starts, because I have a feeling you're going to be a little worn out afterward."

So, she did. And she cleaned her room, and Hailey's room, and she reassured her mom that everything was fine, and she'd make sure that things didn't get too crazy around the house when she went out for a romantic weekend with Mark, and got increasingly jittery--and Hailey had locked up her magic wand, and kept coming into the bathroom to watch while Grace took baths, so she wasn't able to relieve that jitteryness even a little.

On Thursday, Hailey was in her room when she woke up, sitting at her desk, texting. "Finally," she said, when Grace made a confused noise. "Okay. Hands and knees, up on the bed."

It'd started with covert makeouts the first time they'd had a sleepover, two years back, and it'd gone on from there. And while they switched off who was doing stuff to who, most of the time it was Hailey having the ideas, and Grace going along with them, because it was usually stuff that she'd always wanted to try, but hadn't been brave enough to find girls who also wanted to try it. So she immediately recognized the tone of voice which meant that Hailey wanted her to do something.

She got onto her hands and knees, and Hailey pulled down her pyjama bottoms--not too different from what Grace had done in that stupid video--and started caressing her butt.

"Grace?" said Hailey.

"Sorry, sorry," said Grace. "It's a nice butt, though. Anyway. Amazon order came, and thank god parents didn't look at it. So, present for you."

She started rubbing Grace's clit, just soft, slow strokes. Grace moaned, and felt herself opening up. It'd been three days since she'd been allowed to jerk off, and--

And Hailey slipped something inside of her. Round and big, but not too big? "There you go," she said. "It's a bluetooth activated egg! I put the app on your phone already, so just make sure it's on and nearby, or there'll be trouble. Also, also, I did some arts and crafts, so it's not just Amazon presents. Check out your bra."

Grace opened her bureau. Her good bra was covered in duct tape?

"Thumbtacks!" said Hailey. "Come on, put it on!"

Grace got out of her pyjama top and slowly put the bra on. There were like a thousand thumbtacks there, pushed through the bra and held in place by the duct tape. It hurt when she fastened it, and it hurt more when Grace squeezed her breast.

"There, see?" said Hailey. "I mean, it'll get you in the right sort of mood. Anyway, hurry home, and do the shopping. Dips and chips and so on. We'll be in around eight, I think? Anyway. It'll be fun. And if you don't do exactly what we tell you to do, you'll regret it."

The bra still hurt, though.

And then it seemed that Hailey had decided to test her new toy, because the vibrator clicked on. Grace gasped, and grabbed hold of her dresser to steady herself. Stuff inside, even vibrating stuff inside, was never enough to get her off, and obviously Hailey knew that. But it was. . . and it had been three days!

School was agony. The tacks in the bra weren't pushing hard enough to make her bleed, but she couldn't help noticing them, literally all the time. And that was her good bra, and Hailey had basically ruined it, and. . . and that vibrator would go on for five minutes at a time sometimes, and she was sure that everyone could hear the little whir of its motor. And some of those giggly girls were staring at her in the hallway, and she really, really didn't want to do anything with anyone.

But when she was done with school, she went and got chips and dip and pretzels and set them up on paper plates on the dining room table, and she fussed with setting up the living room, and she tried not to vomit. If this was Hailey pranking her, that would be. . . okay, that would be amazing, and she'd forgive her, and maybe possibly some day, if one of Hailey's friends was a reasonable person, and they met beforehand and talked about stuff, maybe . . .

The doorbell rang. If her mom was back, no one would get in trouble, because it was currently like the tamest party she'd ever heard of, and Hailey wouldn't be able to--

"Your maid is quite tardy," said a girl, in a terrible English accent, and there was a chorus of giggles.

Wasn't a prank, and it wasn't her parents coming back early for some reason. Grace ran to the door and opened it. Hailey, and two other girls.

"Knees, please," said Hailey, and blushing furiously, Grace dropped to her knees.

The other two girls looked amazed. "Wow," said one of them, and, "Holy shit," said the other. "I thought you were making it up."

"Yeah, well," said Hailey, as she walked in. "You can kiss my shoe now, Grace."

Grace hesitated, then caught the look on Hailey's face. It wasn't exactly graceful, but she did it. "Good girl," said Hailey, and turned on the vibrator. Grace fought back a moan. "Now Anne and then Sophie."

No way. She wasn't going to--she did. The sneakers they were wearing were pretty grimy, but it was just a kiss, and each time she did, Hailey set the vibrator up a notch.

"Okay, back up, and take off your shirt. Here--that's the bra I was telling you about."

Sophie reached up and grabbed Grace's breast, and squeezed, hard. Grace yelped and pulled away.

"Boo," said Anne. "You're supposed to say, 'Thank you, ma'am,' not 'Ow.'"

"She's right," said Hailey. "Try again, Grace."

Sophie grabbed Grace's other breast. It hurt like hell--could be it had broken the skin that time. "Thank you, ma'am," said Grace, through gritted teeth.

"There, see?" said Hailey. "Anyhow, Melly and Nur are going to be here in like half an hour, so let's go get her dressed up in slut clothing before they show up."

"And also we can teach her manners," said Anne, with an airy gesture. "Good help is so hard to find, isn't it?"

"Well," said Hailey. "She does have a nice round butt. And watch what happens when you turn the vibrator on."

Grace tried to steel herself, but she couldn't help it--when it went on, she went a deeper red, and moaned a little.

"Haha, nice," said Anne. "Anyway. Where the slut clothes at?"

Anne's street accent was worse than her English accent, which wasn't something Grace had believed possible.

The slut clothes were, not surprisingly, in an Amazon box in Hailey's room. Only before she could get into those, she had to get undressed, and the girls were delighted by the marks of the tack bra, and by how wet her pussy had gotten, and also what a pussy looked like after a full Brazilian, which was something that they hadn't seen before, apparently.

Hailey had her display by lying on her back on Hailey's bed, hands under her butt, and legs spread wide. Sophie was more interested in Grace's breasts, so she was sitting further up the bed, kneading them, and pinching Grace's nipples, while Anne and Hailey sat between her legs, and studied her pussy.

"Her inner lips are like, purple," said Anne. "Is that turned on or--"

"Just the way she is," said Hailey. "It's puffy because she's turned on though. And if it was that slimy when she wasn't turned on, she'd be like, leaving a snail trail behind her when she was turned on."

Anne gave a snorting laugh. "How long has it been?"

"Three days," said Hailey. "And she's super scared of this, and was all like, bloo hoo, I don't wanna gang bang. But three days for her is like a month for a normal person."

"Lol," said Anne. She poked Grace's clit, which made her flinch, and then rubbed it, which made her moan, whether or not she wanted to. "Anyhow. Slut clothing?"

Slut clothing was crotchless panties, a short skirt, cheap stockings, a bustier that didn't cover Grace's breasts, and shoes with heels that were way too high. How much money did Hailey's dad give her for fun money?

"Nice, nice," said Hailey when Grace was dressed and had twirled around to show them how it looked. "Anyway. They're going to be here in like five minutes, so get your butt down there, and answer that door when they ring."

"And remember to kiss their feet," said Sophie, as Grace went downstairs.

For a moment, Grace was downstairs by herself. And she was tempted to just pick up and run away. It was a terrible idea, and it would lead her into a worse situation than the one she was in, but it felt like a good idea, for just that moment.

Then Hailey and the other two came downstairs, and then the doorbell rang, and Grace had to wobble over there, to show Hailey's other friends that she was legit a sex slave who was legit going to sex serve them.

The thing was, though, at first it was a lot like a normal high school party. Sitting around drinking soda and eating chips, and gossiping about their classmates, and the tv shows they were watching and so on. Only instead of doing each other's nails, Grace was running around doing their nails and getting felt up. And thanking them for it.

Thanking them each for anything they did to her was one of the rules, and Hailey had added another one--anyone besides Hailey who made Grace come was going to have spend an hour naked and doing what the rest of them told her. Which meant that they were all trying to get her as close as possible, so that the next girl who touched Grace would set her off.

Nur was probably the best at it. She had long, slim fingers, and she would let them trail achingly slowly across Grace's pussy. Also, she was probably also the prettiest. After Hailey. Who was having the time of her fucking life.

And if that was all there was to it, it would've been okay. Only after Grace had painted all the girls' toenails, and had her breasts and pussy handled by each of them, it was time for party games.

"Okay!" said Hailey. "Here we go. First one to make Grace cry is the first one to get oral. Everyone gets a minute, and no tools or anything. Bare hands."

That was more interesting than casting news about Hawaii 5-0. They put their names down on pieces of paper, and pulled them out of a hat. Melly went first, and she started slapping Grace's ass. She didn't want to look like a wimp, and she didn't actually want to lick out some girl that she didn't know, so Grace wasn't going to cry. Not that it was that hard--Hailey hit her ass a lot harder than that.

Then it was Sophie, who went right in after her nipples. That was a lot harder. But they decided that moans didn't count, and tears in her eyes weren't good enough. It had to be full-out crying.

Next up was Nur. She didn't talk or giggle as much as the rest of them, and there was a little bit of a sway in her walk as she went from the couch where she'd been sitting with Melly. Grace found that she was scared of her, in a way that she hadn't been afraid of the other two.

Hailey started the timer on her phone, and Nur knelt down next to Grace, who was waiting on her hands and knees. Then she tucked a lock of hair behind Grace's ear, and whispered to her. "Hailey showed me that video," she said. "She shared it with a lot of people. And now all of them can make you do this, whenever they want."

Grace jerked back, stared at her, wide-eyed. And Nur slapped her across the face. "You were a stupid, and this is it, from here on in."

"But--"

Nur hit her again, on her other cheek, and Grace started crying. Which made all the other girls cheer. Nur stood up, bowed, and then grabbed Grace's hair, pulled her over to the couch, and she unzipped her jeans.

Grace and Hailey had eaten each other out. A lot. That was just about Hailey's favorite thing, and it was pretty great--there were a lot of times when Grace was bored in class, and she'd just daydream about being eaten out, or about eating Hailey out. But Nur looked a little different--her inner lips were tucked inside her outer lips, and she pushed Grace's face into her crotch a lot harder than Hailey did.

But that wasn't the real problem. Hailey had shared that video with a lot of people? If Grace hadn't. . . but Hailey wouldn't. She wouldn't! This was already pushing things too far, but if that got out, it'd be a disaster for Grace and an inconvenience for Hailey, and Hailey didn't like being inconvenienced. It was--

Nur had started off squirming when Grace had started licking her, and it didn't take her long before she stiffened up, her hand so tight in Grace's hair that she probably got a handful of hair to keep as a souvenir.

"So who's next?" asked Sophie.

"Next one to make her cry," said Hailey. "It's way better when her face is wet. But since there's lots of stuff we want to do, may as well let you guys use tools. Anything you've got in your purses."

So Anne hit her breasts with a USB cable, and Hailey sawed on her clit with her comb, and honestly, once she'd started crying, it was a lot easier to get her started again. Sophie was the last one that Grace licked out, and when Sophie came, there was a sudden rush of vaguely foul-tasting liquid that came out into her mouth--she choked and shook her head, and was drenched with it, all down her chest and skirt.

"Okay," said Hailey. "Now tie her up in the closet, and we'll order pizza."

"Aw," said Nur. "She'd be a good tip for the pizza guy."

"Haha," said Anne. "Tip."

Hailey frowned at them. "No, we're not fucking showing her to some dude who might call the cops. Jesus. I've got a good thing going here, and you guys aren't going to mess it up for me."

Right. Right! Hailey was smart, and didn't take chances, and no way she'd shared that video with lots of people. Grace was so reassured that she didn't even mind when they tied her up way more than they needed to tie her up. Though she did mind when Nur got one of those big chip-clip things and put it on her pussy. "So that the vibrator doesn't fall out," she explained. "That girl is way too turned on by this shit."

That hurt. It hurt a little bit going on, and then it hurt more and more, until that faded a bit, to start hurting again every time someone turned the vibrator on, which was a lot. And it hurt enough to bring tears to her eyes when they took her out of the closet and took it off.

Then they made her beg for pizza crusts and left-over fries, and then they made her clean up, and smacked her butt whenever she passed by any of them.

And then Hailey brought out the last bunch of stuff that she'd gotten from Amazon. Four new strap-on dildos, each a different color. They were also different sizes--the banana-yellow one that Nur wore was longer and thinner than the green bumpy one that Sophie had a hard time putting on. Hailey was wearing her usual white one, which was just a little bigger and a little wider than was comfortable, and had the same upward curve as the short wide gray one that Anne was wearing, and Melly had a red one that looked way too big and way too wide, and like a terrible idea all around.

Once they were all strapped in, they tied Grace up on her hands and knees on the coffee table. It wasn't the first time that she'd been tied up on that coffee table--Hailey liked it because when Grace was tied up like that, her butt and her face were at just the right height for fucking--but normally Hailey would just tie her wrists and ankles to the legs of the table. This time, they tied her arms down, and there were ropes going around her stomach, and then around the table, and Anne took out the shoelaces from basically all of Grace's shoes to make sure her fingers and her toes were all securely fastened. While it was nice to get out of those heels, Grace couldn't move pretty much at all--she could get her head up and down, and that was it.

"Okay," said Hailey. "Hands up for everyone who'd just gotten eaten out by a girl for the first time!"

Sophie's hand went up, and so did Melly's. Nobody else's. One of the reasons why Grace had been willing to start making out with her stepsister was because she'd honestly thought there weren't any other girls who'd want to do that. It seemed that she'd made a mistake about that. And about other things.

"Okay!" said Hailey. "You guys get to watch the rest of us, to see how it's done. Can be a little tricky to get it to stay in the right hole, and if you're using her face, you don't want to make her throw up."

"If I'm using her face," said Nur, "I'm not sticking a bit of silicone into it. That was fucking great."

"Heckin' yeah it was," said Hailey. "Got her trained up proper."

"Doe she go ass to mouth?"

"Of course she fucking goes ass to mouth," said Hailey. "She's a sex slave, dummy."

"Okay, dibs on first mouth."

"Fine," said Hailey. "Here's lube, there's tissues--I mean, there's always poop in butts, but we don't need to see that."

And then they started. First it was Anne fucking her pussy while she licked Nur's butt, trying to get her tongue in between her taut cheeks, which was something that she hated, and which she didn't want to do, but which she did because she knew they'd make her regret it if she didn't. And while Anne's dildo was relatively short, she didn't take the vibrator out first, so that the egg was slamming against her insides with every thrust.

When Hailey noticed that, she helpfully turned it on, and Grace's eyes started to roll back. She couldn't come without something on her clit, and they weren't giving her that, and she couldn't, and--

Anne pulled out, and Nur went around to her back, while Hailey pulled a chair over and sat down in front of her. She guided Grace's head down to her strap-on, but she didn't force her to take the whole length--just to keep a bit in her mouth, as her friends fucked her.

Nur was the first one to put it into Grace's butt, and that really hurt. She didn't use enough lube--given how much she'd known about everything else, that was probably on purpose--and the curve in her dildo didn't fit right with the way that she was set up, so Grace was whining around Hailey's dick and trying to move, just a little, just enough to make it comfortable.

"Sh," said Hailey, patting her head. "Sh. It's going to get a lot worse. Hey, Sophie--you want to make her come while Melly fucks her ass?"

Sophie sighed. "Yeah, I'm not going to get undressed and do what you guys tell me. You're all mean."

"Fine," said Hailey. "You've avoided my cunning trap. But do it anyway. New rule--Sophie gets to make a lady orgasm for the first time, and Melly gets to fuck a girl's ass for the first time, and I get to watch my sister get double-teamed the way she deserves, and nobody except Grace has to be naked or anything."

"Yeah okay," said Sophie. Melly didn't say anything, but the lube was right next to Grace's shoulder. She could see Melly slathering it on that red monster that Hailey had given her.

Hailey leaned forward, which made her dildo pop out of Grace's mouth as Nur pulled out of Grace's butt. "Melly really likes your butt," she said. "She's been fantasizing about it for weeks."

Every muscle in Grace's body was trembling. It had been three days, and it had been a hell of a night, and Sophie had already started playing with her breasts, just running her hands over them. Grace closed her eyes, and bit her lip, and hoped that it wasn't going to hurt as much as it was going to hurt.

The hoping didn't work. There was enough lube on the dildo, but that wasn't entirely good, because if there hadn't been, it might not have gotten in, it was that big. And Melly didn't start slow, either. A few pushes in, to see how it worked, and then she was grabbing onto Grace's hips, and fucking so hard and fast Grace . . it hurt too much.

"Please, Hailey," said Grace, looking into her step-sister's clear blue eyes. "Please stop this, please, it hurts."

"I know," said Hailey. "I told them you were a big baby about being ass-fucked. Don't worry, you can say whatever you want, but they know not to listen. Oh, and also they know that you cry after sex, so that's not a problem either."

"Hailey, I did, I did everything you wanted, and I don't. Please? I'll. . . I'll fuck your friends for you, Hailey, I just. . . maybe even just a smaller one--"

"No," said Hailey. "Oh, man. Melly's face. Hold on, hold on--"

"But I--"

Hailey wasn't listening. She got her phone out, and took a picture. It was of Melly, and her eyes were closed, her hair thrown back, and her small, pale face looked absolutely ecstatic. She looked beautiful, but Grace couldn't take it, she couldn't--she was tearing her apart.

"Grace, please, I--oh!"

Sophie had moved from Grace's breasts to her clit. And it hurt too much, but Grace was way, way too wound up to resist it. Hailey turned on the app on her phone that controlled the vibrator, and that added to the pressure that was building up, in her thighs, in her pussy, in her stomach.

"Never actually seen anyone come from fucking with a strap-on, but. . . there we go," said Hailey, as Melly's hands scraped along Grace's hips, and she thrust deep inside her, and held there. Grace was coming too, and she hated it, hated that it was with people who she didn't know, hated that it hurt as much as it did, hated that it felt as good as it did.

After that, it was getting late, and nobody wanted to go through the trouble of untying Grace before they left. Hailey sat next to her, and made her lick out all of the friends who came to the party, one after the other, then she let her hang down in her bonds, as they said their goodbyes and left.

For a little while, Grace was by herself, in a living room littered with the detritus of the party--crusts that she hadn't caught, chip fragments in the carpet, and so on. She was shuddering, she would've curled up if she could've. But she couldn't even move her toes. She had to wait for Hailey to come back, and when she did, she didn't untie her either.

"See," said Hailey. "Told you that you would do it."

Grace cried, not having any other answer to that.

"So, I'd say sorry, but when Melly was fucking you. . . that was literally the hottest thing that I've ever seen. Wow."

Grace let out a sob, and Hailey patted her head. "Here, why don't you suck on a dildo for a bit. You like that; it cheers you up."

She did not like that. But she sucked, like she was told. "Oh, and Nur was lying about the tape. You know that."

She did. Grace nodded.

"But I still have the tape, and you're still going to do what I say, right?"

Grace gave a defeated little nod, still sucking the dildo that Hailey was holding--the one that Anne had used, which tasted like her pussy. "So after you wake up tomorrow, you're going over to Melly's house for a visit. I'll give you toys to take along, and her boyfriend is probably going to be there."

Grace looked up at Hailey. Her boyfriend? But she wasn't--

"Sh," said Hailey, stroking her hair. "Sh. You wanted a summer job, right? And Melly's giving me fifty bucks to use you all morning. Tell you what--if you do a good job, I'll give you five."

With one hand, Hailey was feeding her that dildo. But at the look in Grace's eyes, Hailey's other hand went down into her skirt. "It's going to be great," she said.


End file.
